Question: What Class IB flammable liquid has the highest ceiling exposure limit?
Paraphrase: Which Class IB liquid has the highest exposure limit?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q21009055 . ?ent wdt:P2405 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: toluene, Octane, 2,2-dimethylbutane, n-heptane, petroleum ether